Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G69/00—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one other conversion process
  • C10G69/02—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one other conversion process plural serial stages only
  • C10G69/12—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one other conversion process plural serial stages only including at least one polymerisation or alkylation step
  • C10G69/126—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one other conversion process plural serial stages only including at least one polymerisation or alkylation step polymerisation, e.g. oligomerisation
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C5/00—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms
  • C07C5/32—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by dehydrogenation with formation of free hydrogen
  • C07C5/327—Formation of non-aromatic carbon-to-carbon double bonds only
  • C07C5/333—Catalytic processes
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C11/00—Aliphatic unsaturated hydrocarbons
  • C07C11/12—Alkadienes
  • C07C11/173—Alkadienes with five carbon atoms
  • C07C11/18—Isoprene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F136/00—Homopolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds
  • C08F136/02—Homopolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds
  • C08F136/04—Homopolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated
  • C08F136/08—Isoprene
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G49/00—Treatment of hydrocarbon oils, in the presence of hydrogen or hydrogen-generating compounds, not provided for in a single one of groups C10G45/02, C10G45/32, C10G45/44, C10G45/58 or C10G47/00
  • C10G49/02—Treatment of hydrocarbon oils, in the presence of hydrogen or hydrogen-generating compounds, not provided for in a single one of groups C10G45/02, C10G45/32, C10G45/44, C10G45/58 or C10G47/00 characterised by the catalyst used
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G50/00—Production of liquid hydrocarbon mixtures from lower carbon number hydrocarbons, e.g. by oligomerisation
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/10—Feedstock materials
  • C10G2300/1088—Olefins
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/20—Characteristics of the feedstock or the products
  • C10G2300/30—Physical properties of feedstocks or products
  • C10G2300/302—Viscosity
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2400/00—Products obtained by processes covered by groups C10G9/00 - C10G69/14
  • C10G2400/22—Higher olefins

Definitions

• the present invention relates to a process for obtaining, from a C5 cut from catalytic cracking on a fluid bed, a C5 cut enriched in isoprene and purified which can be used to form a medium for the selective polymerization of isoprene.
• the invention also relates to a process for obtaining an isoprene homopolymer having in particular a high cis-1,4 linkage rate and an inherent viscosity, from a polymerization medium comprising isoprene and at minus a methyl butene, such as said C5 catalytic cracking cut on a fluid bed enriched in isoprene and purified.
• C5 catalytic cracking cuts on a fluid bed usually contain isoprene according to a mass fraction less than 1%.
• ⁇ -olefins comprising, on the one hand, ⁇ -olefins such as butene-1, 3-methyl-butene-1, pentene-1, 2-methyl butene-1 and, on the other hand, ⁇ -olefins such as butene-2, pentene-2 and methyl-2-butene-2; - according to a mass fraction typically between 55% and 30%, alkanes comprising Pisopentane in the majority and n-pentane in the minority, and according to a mass fraction typically less than 1%, dienes such as cyclopentadiene, pentadiene-1,3 and pentadiene-l 5 4 5 and other compounds such as acetylenic compounds.
• mono-olefins comprising, on the one hand, ⁇ -olefins such as butene-1, 3-methyl-butene-1, pentene-1, 2-methyl butene-1 and, on the other hand, ⁇ -olefins such as but
• C5 catalytic cracking cuts on a fluid bed should not in particular be confused with C5 naphtha steam cracking cuts, which typically contain isoprene in a mass fraction ranging from 10% to 30%, mono-olefins (- olefins and ⁇ -olefins) according to a mass fraction ranging from 20% to 40%, dienes such as cyclopentadiene and pentadienes according to a mass fraction ranging from 20% to 30%, and, as a minority, alkanes, limonene and acetylenic and aromatic compounds.
• This catalytic system is based on a conjugated diene monomer, a rare earth salt of an organic phosphoric acid in suspension in an inert, saturated hydrocarbon solvent of aliphatic or alicyclic type, of an alkylating agent consisting of an aluminum alkyl of formula A1R or HA1R 2 , in which Al represents the aluminum atom, H represents a hydrogen atom and R represents a hydrocarbon radical, according to a molar ratio (alkylating agent / rare earth salt ) varying from 1 to 5, and a halogen donor consisting of an alkylaluminum halide.
• this C5 cut must also be enriched in isoprene so that the mass fraction of isoprene in the enriched cut is close to 100%, typically greater than 99%.
• certain compounds of this enriched C5 cut such as methyl butenes, harm the yield of the isoprene polymerization reaction.
• the enriched cut must be practically free of pentadiene-1,3 and -1,4, known to penalize the kinetics of polymerization of isoprene compared to that of isoprene taken in isolation.
• this obtaining of a mass fraction of isoprene close to 100% in a C5 section of catalytic cracking on a fluid bed can be obtained, in a first step, by decomposition of an amyl ether obtained by reaction d 'an alcohol with this C5 cut to obtain a mass fraction of methyl butenes close to 100% in the C5 cut thus treated and purified, then, in a second step, by oxidative dehydrogenation of methyl butenes to isoprene.
• the object of the present invention is to overcome this drawback, and it is achieved in that the applicants have surprisingly discovered that a catalytic system based:
• alkylating agent consisting of an aluminum alkyl of formula A1R 3 or HA1R 2 , in which.
• Al represents the aluminum atom
• H represents a hydrogen atom
• the radicals R identical or different, linear or branched, represent hydrocarbon groups having from 1 to 8 carbon atoms, and - from a donor halogen consisting of an aluminum alkyl halide, said salt being in suspension in at least one inert, saturated and aliphatic or alicyclic hydrocarbon solvent which is included in said catalytic system, and the molar ratio (alkylating agent / salt of rare earth) belonging to a domain ranging from 1 to 5, allows the selective polymerization of isoprene with a high catalytic activity to obtain a polyisoprene with a high rate of cis-1,4 linkages, starting from cutting
• a process for obtaining said final C5 cut enriched in isoprene and purified which can be used to form a medium for the selective polymerization of isoprene in the presence of said catalytic system, from said cut C5 initial catalytic cracking on a fluid bed, includes:
• this mass fraction of methyl butenes in this intermediate C5 cut is extremely reduced compared to the mass fractions in methyl butenes close to 100% which characterize the C5 cuts before dehydrogenation used in the known processes for enrichment in isoprene of catalytic cracking sections on a fluid bed, for the selective polymerization of isoprene with a high yield with a view to obtaining a polyisoprene with a high rate of cis-1,4 linkages.
• said intermediate C5 cut is depleted in n-pentenes so that it comprises said n-pentenes according to a mass fraction of less than 0.1%.
• the final C5 fraction comprises 1,3-pentadiene and pentadiene-l 5 4 according to mass ratios (1,3-pentadiene / isoprene) and (1,4-pentadiene / isoprene) which must be less than or equal to 0.5% and 0.2%, respectively, to be able to selectively polymerize isoprene from this cut final with satisfactory conversion kinetics which is close to that relating to the isolated polymerization of isoprene (ie the polymerization medium comprising only the solvent and isoprene) and to obtain a polyisoprene of high viscosity similar to that of the polyisoprene obtained in isolation .
• said process for obtaining said final C5 cut enriched in isoprene comprises a catalytic hydrogenation reaction, such as a catalytic hydrogenation using a palladium-based catalyst, which is applied to said initial C5 cut and which produces said intermediate C5 cut.
• a catalytic hydrogenation reaction such as a catalytic hydrogenation using a palladium-based catalyst
• the mass ratio (methyl butenes / isoprene) in said final and purified C5 cut is equal to or greater than 50%.
• the mass ratio (mono-olefins / isoprene) in said final and purified C5 cut can advantageously be greater than 50%.
• the final C5 cut is subjected to purification operations comprising:
• the final C5 cut and thus purified comprises in particular, as methyl butenes, 2-methyl-butene-2 3 and that it also comprises minimal quantities:
• the mass ratio (disubstituted alkynes / isoprene) being preferably less than or equal to 0.7%
• the mass ratio (true alkynes / isoprene) in the final and purified C5 cut is preferably less than or equal to 15 ppm, of cyclopentadiene, the mass ratio (cyclopentadiene / isoprene) in this final and purified C5 cut preferably being less than or equal to 5 ppm.
• the present invention also relates to a process for obtaining an isoprene homopolymer having a cis-1,4 linkage rate equal to or greater than 98.0%, which is such that it comprises the reaction of said system.
• catalytic according to the invention in a polymerization medium comprising isoprene and at least one methyl butene, so that the mass ratio (methyl butene (s) / isoprene) is equal to or greater than 50% and advantageously equal to or greater than 100%.
• the polymerization medium comprises at least one mono-olefin and the mass ratio (mono-olefin (s) / isoprene) is higher 50% in this polymerization medium.
• said methyl butenes include 2-methyl-2-butene.
• the mass ratio (2-methyl-2-butene / isoprene) in said polymerization medium is equal to or greater than 20% and, even more preferably, equal to or greater than 50%.
• C5 cuts of catalytic cracking on a fluid bed and the said final and purified C5 cuts according to the present invention which result therefrom are characterized in that they always comprise 2-methyl-2-butene.
• said methyl butenes include at least 2-methyl-butene-1 and 2-methyl-butene-2, the mass ratio (2-methyl-butene-1 / isoprene) and the mass ratio (2-methyl-butene -2 / isoprene) each being between 20 and 60%.
• the mass fraction of isoprene in said polymerization medium is less than 30% and advantageously less than or equal to 10%.
• said process comprises the following steps: (i) obtaining, from an initial C5 cut from catalytic cracking on a fluid bed, an intermediate C5 cut comprising methyl butenes according to a mass fraction of less than 30% and advantageously less than or equal to 20%,
• the mass ratio (monoolefin (s) / isoprene) is greater than 50% in this polymerization medium.
• said step (i) comprises a catalytic hydrogenation, such as a catalytic hydrogenation using a catalyst based on palladium.
• said intermediate C5 cut is depleted in n-pentenes such that it comprises said n-pentenes according to a mass fraction of less than 0.1%
• said final C5 cut comprises pentadiene- 1,3 and 1,4-pentadiene in mass ratios (1,3-pentadiene / isoprene) and (1,4-pentadiene / isoprene) which must be less than or equal to 0.5% and 0.2 respectively % for the above reasons.
• said final and purified C5 cut comprises isoprene according to a mass fraction of less than 30% and advantageously less than or equal to 10%.
• the mass ratio (methyl butenes / isoprene) in said final and purified C5 cut is equal to or greater than 50%.
• the polymerization reaction of isoprene is carried out at a temperature less than or equal to 5 ° C., so that said homopolymer isoprene presents a rate of cis-1,4 sequences, measured according to the techniques of nuclear magnetic resonance of carbon 13 or assay by infrared medium, which varies from 99.0% to 99.6%.
• polyisoprenes are obtained, the cis-1,4 chain rates, measured by one or the other of the above techniques, are equal to or greater than 99.3% and even more advantageously belong to a range ranging from 99.3% to 99.6%, when the polymerization is carried out at a temperature ranging from -55 ° C to -20 ° C.
• polyisoprenes are obtained whose cis-1 linkage rates, 4, also measured by one or other of the abovementioned techniques, are equal to or greater than 99.5% and are for example equal to 99.6%, when the polymerization is carried out at a temperature ranging from -55 ° C. at -45 ° C.
• the isoprene homopolymers which are obtained by said process have inherent viscosities, measured at 0.1 g / dl in toluene at 25 ° C, which are greater than 3 dl / g , advantageously at 4 dl / g.
• the catalytic system according to the invention has the advantage of imparting, to the isoprene polymerization reaction, practically the same advantageous kinetics of isoprene conversion and, to the polyisoprenes obtained, practically the same high values of viscosity inherent in given conversion rates, whether or not the polymerization medium comprises said methyl butenes.
• the molar ratio (alkylating agent / rare earth salt) belongs to a range ranging from 1 to 2.
• said salt ' is a rare earth tris [bis (2-ethylhexyl) phosphate] of earth (s) Rare (s), such as tris [bis (2- neodymium ethylhexyl) phosphate].
• said catalytic system satisfies at least one of the following conditions: (a) said catalytic system comprises said rare earth metal (s) according to a concentration belonging to a range ranging from 0.01 to 0.06 mol / l,
• conjugated diene monomer (c) the molar ratio (conjugated diene monomer / rare earth salt) varies from 15 to 70, (d) said conjugated diene monomer is butadiene,
• said alkylating agent is diisobutylaluminum hydride
• said halogen donor is diethylaluminum chloride.
• conjugated diene monomer which can be used to "preform" the catalytic system according to the invention, mention may be made of 1, 3-butadiene, preferably.
• 2-methyl 1, 3-butadiene or isoprene
• the 2, 3-di (C1 to C5 alkyl) 1, 3-butadiene such as for example 2, 3 dimethyl-1, 3- butadiene, 2, 3-diethyl-1, 3 -butadiene, 2-methyl 3-ethyl 1, 3 -butadiene, 2-methyl 3-isopropyl 1, 3-butadiene, phenyl 1, 3 -butadiene, 1, 3-pentadiene, 2, 4-hexadiene, or any other conjugated diene having between 4 and 8 carbon atoms.
• said rare earth salt consists of a non-hygroscopic powder having a slight tendency to agglomerate at room temperature.
• the inert hydrocarbon solvent in which said rare earth salt is in suspension is an aliphatic or alicyclic solvent of low molecular weight, such as cyclohexane, methylcyclohexane, n-heptane, or a mixture of these solvents.
• the solvent used for the suspension of the rare earth salt is a mixture of an aliphatic solvent of high molecular weight comprising a paraffinic oil, for example petrolatum oil, and d a low molecular weight solvent such as those mentioned above (for example methylcyclohexane).
• a paraffinic oil for example petrolatum oil
• a low molecular weight solvent such as those mentioned above (for example methylcyclohexane).
• This suspension is produced by dispersive grinding of the rare earth salt in this paraffinic oil, so as to obtain a very fine and homogeneous suspension of the salt.
• said catalytic system comprises the rare earth metal according to a concentration belonging to a range ranging from 0.01 to 0.06 mol / 1, for example equal or substantially equal to 0.02 mol / 1.
• alkylating agent corresponding to the formula A1R 3 or HA1R which can be used in the catalytic system according to the invention, mention may be made of aluminum alkyls such as:
• trialkylaluminiums for example triisobutylaluminium, or
• this alkylating agent preferably consists of diisobutylaluminum hydride (called HDiBA in the remainder of this description).
• HDiBA diisobutylaluminum hydride
• CDEA diethyl aluminum chloride
• the molar ratio (halogen donor / rare earth salt) can have a value ranging from 2.0 to 3.5.
• the process for preparing said catalytic system consists of:
• Nd 2 O 3 + 6 HCl + 9 H 2 O ⁇ 2 NdCl 3 , 6H 2 O reaction is very exothermic.
• the solution is brought to the boil with stirring for 30 minutes, in order to remove the excess HC1.
• the aqueous solution of NdCl 3 is clear and purple in color. There remains no insoluble product (Nd 2 O).
• the neodymium salt thus washed is dried in an oven at 60 ° C, under vacuum and with air flow for 72 hours.
• the catalytic system comprises a phosphate salt of neodymium as synthesized according to paragraph 1) above, which is in suspension in an inert hydrocarbon solvent of low molecular weight (consisting of methylcyclohexane, "MCH" for short below).
• the catalytic system is characterized by the following relative molar ratios, relative to the neodymium salt:
• Nd / butadiene salt (Bd) / HDiBA / CDEA 1/30 / 1.8 / 2.6.
• the final concentration of Nd in the catalytic system is 0.02 M.
• neodymium salt in powder form, are poured into a reactor previously cleaned of its impurities. This salt is then subjected to nitrogen sparging through the bottom of the reactor, for 15 min.
• Butadiene is then introduced into the reactor (according to the molar salt / butadiene ratio of 1/30 mentioned in paragraph 2) a) above) at the temperature of 30 ° C, with a view to the "preformation" of the catalytic system.
• HDiBA is then introduced into the reactor as an alkylating agent for the neodymium salt, at a concentration of approximately 1 M in the MCH.
• the duration of the alkylation is 30 min. and the temperature of the alkylation reaction is 30 ° C.
• CDEA is then introduced into the reactor as a halogen donor, at a concentration of approximately 1 M in the MCH.
• the temperature of the reaction medium is brought to 60 ° C.
• a solution of the catalytic system is thus obtained.
• the reactor is emptied and this solution is transferred to a 750 ml "Steinie" bottle, previously washed, dried and subjected to sparging with nitrogen.
• the catalytic solution is stored under a nitrogen atmosphere in a freezer, at a temperature of -15 ° C.
• Table 1 below contains the characteristics of the catalytic system and its preparation process.
• the polymerization reactor is a 250 ml "Steinie" bottle, which contains
• the polymerization of isoprene is carried out in cyclohexane at 50 ° C. under an inert nitrogen atmosphere (the cyclohexane having been subjected beforehand to bubbling with nitrogen for 10 minutes).
• control tests according to the invention were carried out using 2.3 ml of said catalytic system, ie an amount of catalytic base in neodymium of 450 micromoles per 100 grams of isoprene monomer ( ⁇ Mcm for short).
• each solution extracted in an oven at 60 ° C. under vacuum (at a pressure of 200 mm Hg) was dried for about 18 hours, with a slight stream of nitrogen.
• the measurement of the rate of conversion of isoprene to polyisoprene as a function of the reaction time describes the kinetics of polymerization for each “control” test and according to the invention.
• a polymerization medium was used in this test according to the invention comprising approximately 10% of isoprene, 5% of 2-methyl-butene-1, 5% of 2-methyl-butene-2 and 80% of cyclohexane (mass fractions) . 15 ml (10.2 g) of the isoprene prepared in ⁇ IL 1) above are used in this test
• the 2-methyl-butene-1 used is obtained by purification, carried out by means of a dropwise passage over an alumina column, of a 2-methyl-butene-1 at about 95% pure and marketed by the company Fluka. . 7.8 ml of 2-methyl-butene-1 is used, ie 5.1 g.
• the 2-methyl-butene-2 used is obtained by purification, carried out by means of a dropwise passage over an alumina column, of a pure methyl-2-butene-2 at about 85% from the company Fluka (this 2-methyl-2-butene was determined by gas chromatography at 93% purity). 7.7 ml of 2-methyl-2-butene are used, which is also 5.1 g. Table 3 below details the results obtained for this test according to the invention. Table 3:
• Tables 2 and 3 show that the catalytic system according to the invention, based on a conjugated diene monomer, of a rare earth salt of an organic phosphoric acid suspended in an inert and saturated hydrocarbon solvent, of a alkylating agent consisting of an aluminum alkyl of formula A1R 3 or HA1R 2 with a molar ratio (alkylating agent / salt) ranging from 1 to 5, and of a halogen donor consisting of an alkyl aluminum halide , allows to selectively polymerize isoprene in the presence of methyl-2 butene-1 and methyl-2 butene-2 with a mass ratio (methyl butenes / isoprene) equal to 100% (the mass ratios (methyl-2 butene-1 / isoprene) and (2-methyl-2-butene / isoprene) each being 50%), for obtaining a polyisoprene having a rate of cis-1,4 chains equal to or greater than 98.0% and
• an initial rough cut C5 A or B of catalytic cracking on a fluid bed was subjected to a hydrogenation reaction, which is carried out the following manner according to an exemplary embodiment of the invention.
• a hydrogenation reaction which is carried out the following manner according to an exemplary embodiment of the invention.
• a 750 ml bottle are introduced 1 g of catalyst based on palladium and calcium carbonate (of formula Pd / CaCO and containing 5% Pd by weight) and 100 ml of the initial C5 cut.
• the bottle being capped under an initial pressure of 4 bars of hydrogen and being stirred at 25 ° C., the hydrogen pressure is adjusted to 4 bars every hour for 3 hours.
• the total reaction time is 6 hours and 30 minutes.
• This hydrogenation reaction has the particular effect of hydrogenating the n-pentenes contained in the initial cut according to a determined hydrogenation rate T, so as to reduce the amount of n-pentenes in the intermediate hydrogenated cut in view of the second dehydrogenation step which has the effect of transforming these n-pentenes into pentadienes - 1,3 and -1,4.
• the intermediate cut Al obtained which is intended to be subjected to the dehydrogenation reaction with a view to its enrichment in isoprene, comprises a mass fraction of methyl butenes (less than 30%) which is much lower than the near mass fraction 100% which is usually required for dehydrogenation, in order to obtain a final cut which can be used for the homopolymerization of isoprene.
• the hydrogenation made it possible to deplete the initial cut A in n-pentene before dehydrogenation so that the intermediate cut Al comprises less than 0.1% of n-pentenes, while said initial cut A contained it almost 20%.
• each of the intermediate cuts B2 to B6 obtained intended to be subjected to a dehydrogenation with a view to its enrichment in isoprene, comprises a mass fraction of methyl butenes (less than 30%, or even less than 20% for the B6 cut) much lower than the mass fraction close to 100% usually required before dehydrogenation, to obtain a final cut which can be used to homopolymerize isoprene.
• the hydrogenation according to rates T2 to T5 did not make it possible to deplete the initial cut B into n-pentenes before dehydrogenation so that each intermediate cut comprises less than 0.1% of n-pentenes.
• the intermediate cuts B2 to B5 cannot be used for obtaining final cuts according to the invention comprising at most 0.5% of 1,3-pentadiene and at most 0.2% of 1,4-pentadiene , a necessary condition to be able to selectively polymerize isoprene with satisfactory conversion kinetics close to that relating to the isolated polymerization of isoprene and to obtain a polyisoprene of viscosity similar to that of the polyisoprene obtained in isolation.
• the hydrogenation of the initial cut B according to the rate T6 made it possible to deplete the latter in n-pentenes before dehydrogenation, so that the intermediate cut B6 thus obtained comprises less than 0.1% of n-pentenes and therefore conforms to the invention.
• the intermediate cuts A1, B5 and B6 were subjected to dehydrogenations, for example implemented as follows.
• This intermediate cut Al is introduced into a reactor containing a 140 ml catalytic bed heated to a temperature between 600 ° C and 700 ° C, under streams of water vapor and nitrogen preheated to 650 ° C.
• the flow rates of the intermediate cut A1, of the steam and of the nitrogen are respectively 1.63 ml / min., 1460 ml / min. and 3.76 ml / min.
• the catalytic bed is composed of iron oxide, chromium and potassium carbonate and it is marketed by SHELL under the name "Shell 105".
• the final cut Al ′ is in particular characterized in that it comprises: isoprene according to a mass fraction practically equal to 10%, methyl butenes according to a mass ratio (methyl butenes / isoprene) of 65%, mono-olefins according to a mass ratio (mono-olefins / isoprene) of 85%.
• the hydrogenation step by the significant reduction in the rate of n-pentenes which it generates, makes it possible to minimize the rate of pentadienes in the final cut A1 '.
• the mass ratios (pentadiene-1,3 / isoprene) and (pentadiene-1,4 / isoprene) are respectively less than 0.5% and 0.2% in the final cut Al ', which makes that -It can be used after purification (intended to eliminate disubstituted alkynes, true alkynes and cyclopentadiene) for the selective polymerization of isoprene.
• the final cut A'I containing 3.42 g of isoprene is polymerized using the “preformed” catalytic system according to the invention, described in ⁇ I-2) a), by operating according to the method and the conditions described in ⁇ II, except that a quantity of neodymium catalytic base of 1170 micromoles is used per 100 grams of isoprene monomer and that the polymerization is carried out for 220 minutes.
• the cis rate measured by NMR analysis of the carbon 13 of the polyisoprene is 98.1% Polydispersity index measured by SEC: 2.6 c) Dehydrogenation of the intermediate section B5 to obtain three final sections B5 ', B5 "and B5'" not in accordance with the invention:
• Table 8 details the compositions of three final cuts B5 ', B5 ", B5'” respectively obtained by dehydrogenations applied to the intermediate cut B5 mentioned above according to ⁇ III. 2) a) above, at three temperatures of 625 ° C, 650 ° C and 675 ° C.
• each final cut B5 ', B5 “, B5'” comprises isoprene according to a mass fraction of less than 15% and that the mass ratio (methyl butenes / isoprene) inside the final cuts B5 'and B5 "is approximately 60% and 50%, respectively.
• Table 9 details the compositions of final cuts according to the invention B6 ', B6 ", B6'” respectively obtained by dehydrogenations applied to the intermediate cut B6 according to ⁇ III. 2) a) above, at temperatures of 600, 625 and 650 ° C.
• each final cut B6 ', B6 "and B6'” is characterized in that it comprises isoprene according to a mass fraction practically equal to or less than 10%. It will also be noted that the final sections B6 ' 3 B6 "comprise methyl butenes according to a mass ratio (methyl butenes / isoprene) practically equal to or greater than 50%.
• a catalytic dehydrogenation of an initial C5 cut C was carried out directly as described in ⁇ III. 2) a) above, to obtain a final C5 cut C enriched with isoprene.
• the ratio between the levels of 3-4 and 1-4 is determined using ethylene carbons.
• the content of 1-4 trans and 1-4 cis sequences in the polyisoprene is calculated with the aliphatic carbons.
• APPENDIX 2 Determination of the molecular mass distribution of the elastomers obtained by the size exclusion chromatography (SEC) technique.
• Size exclusion chromatography makes it possible to physically separate the macromolecules according to their size in the swollen state on columns filled with porous stationary phase.
• the macromolecules are separated by their hydrodynamic volume, the largest being eluted first.
• the apparatus used is a “WATERS, model 150C” chromatograph.
• the elution solvent is tetrahydrofuran, the flow rate of 0.7 ml / min, the system temperature of 35 ° C and the analysis time of 90 min.
• SHODEX KS807 trade names "SHODEX KS807”
• WATERS type STYRAGEL HMW7 two
• the injected volume of the polymer sample solution is 100 ⁇ l.
• the detector is a "WATERS model RI32X” differential refractometer and the operating software for the chromatographic data is the “WATERS MILLENIUM” system (version 3.00).
• each C5 cut is carried out from an injected volume of 0.2 ⁇ l without prior dilution, so as not to saturate the response of the flame ionization detector (FID) which is used.
• FID flame ionization detector
• ⁇ A; sum of all the compounds i eluted (identified and unidentified).

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• General Chemical & Material Sciences (AREA)
• Polymers & Plastics (AREA)
• Medicinal Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
• Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
• Polymerization Catalysts (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Preparation Of Compounds By Using Micro-Organisms (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=32605936

Family Applications (1)

Country Status (16)

Families Citing this family (12)

Family Cites Families (17)

• 2003
  • 2003-01-22 FR FR0300694A patent/FR2850101B1/fr not_active Expired - Fee Related
• 2004
  • 2004-01-19 BR BRPI0406845-9A patent/BRPI0406845B1/pt not_active IP Right Cessation
  • 2004-01-19 EP EP04703173A patent/EP1587777B1/de not_active Expired - Lifetime
  • 2004-01-19 JP JP2006500590A patent/JP5005337B2/ja not_active Expired - Fee Related
  • 2004-01-19 CN CN200480002696A patent/CN100590137C/zh not_active Expired - Fee Related
  • 2004-01-19 ES ES04703173T patent/ES2304600T3/es not_active Expired - Lifetime
  • 2004-01-19 AU AU2004205481A patent/AU2004205481B2/en not_active Ceased
  • 2004-01-19 MX MXPA05007659A patent/MXPA05007659A/es active IP Right Grant
  • 2004-01-19 WO PCT/EP2004/000343 patent/WO2004065339A1/fr not_active Ceased
  • 2004-01-19 CA CA002513557A patent/CA2513557A1/fr not_active Abandoned
  • 2004-01-19 AT AT04703173T patent/ATE389624T1/de not_active IP Right Cessation
  • 2004-01-19 DE DE602004012526T patent/DE602004012526T2/de not_active Expired - Lifetime
  • 2004-01-19 KR KR1020057013646A patent/KR101315090B1/ko not_active Expired - Fee Related
  • 2004-01-19 RU RU2005126423/04A patent/RU2351612C2/ru not_active IP Right Cessation
  • 2004-01-19 CN CN2007100913560A patent/CN101028989B/zh not_active Expired - Fee Related
• 2005
  • 2005-07-12 ZA ZA200505582A patent/ZA200505582B/en unknown
  • 2005-07-21 US US11/185,680 patent/US7157533B2/en not_active Expired - Lifetime

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events